util/http.go

package util

import (
	"compress/gzip"
	"context"
	"crypto/x509"
	"encoding/json"
	"encoding/xml"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"crypto/tls"
)

const (
	// RequestTimeOut http request timeout (second)
	RequestTimeOut = 30
)

// RouterHandler hander
type RouterHandler struct {
	Method string
	Router string
	Hander http.Handler
}

// Message HTTP response
type Message struct {
	StatusCode int
	Body       []byte
	Header     http.Header
	Cookies    []*http.Cookie
}

func header(w http.ResponseWriter, contentType string) {
	w.Header().Set(`Content-Type`, contentType)
	w.Header().Set(`X-Powered-By`, LibName+`/`+LibVersion)
	w.WriteHeader(http.StatusOK)
}

// Redirect redirect
func Redirect(w http.ResponseWriter, url string) {
	w.Header().Set(`Location`, url)
	w.WriteHeader(http.StatusFound)
}

// GetRealIP get real IP from Request
func GetRealIP(req *http.Request) (ip string) {
	if ips := req.Header["X-Real-Ip"]; ips != nil {
		ip = ips[0]
	}
	return
}

// WriteJSON response JSON data.
func WriteJSON(w http.ResponseWriter, response interface{}) error {
	header(w, `application/json; charset=utf-8`)
	return json.NewEncoder(w).Encode(response)
}

// WriteXML response XML data.
func WriteXML(w http.ResponseWriter, response interface{}) error {
	header(w, `application/xml; charset=utf-8`)
	return xml.NewEncoder(w).Encode(response)
}

// WriteBytes response bytes
func WriteBytes(w http.ResponseWriter, response interface{}) error {
	header(w, `text/html; charset=utf-8`)
	w.Write(response.([]byte))
	return nil
}

// WriteBytesContentType response bytes and Content-Type
func WriteBytesContentType(w http.ResponseWriter, response interface{}, contentType string) error {
	header(w, contentType)
	w.Write(response.([]byte))
	return nil
}

// WriteCtxJSON response JSON data.
func WriteCtxJSON(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	return WriteJSON(w, response)
}

// WriteCtxXML response XML data.
func WriteCtxXML(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	return WriteXML(w, response)
}

// WriteCtxBytes response text data.
func WriteCtxBytes(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	return WriteBytes(w, response)
}

// ResponseJSON reply JSON
func ResponseJSON(reply *ReplyData, err error, req *http.Request, w http.ResponseWriter) error {
	if err != nil {
		return WriteJSON(w, ErrReplyData(ErrException, err.Error()))
	}
	return WriteJSON(w, reply)
}

// HTTPListenAndServe new server and start
func HTTPListenAndServe(addr string, router http.Handler) {
	server := &http.Server{
		Addr:           addr,
		Handler:        router,
		ReadTimeout:    30 * time.Second,
		WriteTimeout:   30 * time.Second,
		MaxHeaderBytes: 1 << 20,
	}
	// Interrupt handler.
	errc := make(chan error)
	go func() {
		c := make(chan os.Signal)
		signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
		errc <- fmt.Errorf("%s", <-c)
	}()

	// HTTP transport.
	go func() {
		log.Println("HTTP Server listen on", addr)
		//logger.Log("Protocol", "HTTP", "addr", addr)
		errc <- server.ListenAndServe()
		log.Println("Exit HTTP server", "Quit")
	}()

	// Run!
	log.Println("Exit", <-errc)
}

func newRequest(method, uri, certPath, keyPath string, header map[string]string, body io.Reader) (res *http.Response, err error) {
	t := &http.Transport{
		Dial: func(netw, addr string) (net.Conn, error) {
			conn, err := net.DialTimeout(netw, addr, time.Second*RequestTimeOut)
			if err != nil {
				return nil, err
			}
			conn.SetDeadline(time.Now().Add(time.Second * RequestTimeOut))
			return conn, nil
		},
		ResponseHeaderTimeout: time.Second * RequestTimeOut,
	}

	if certPath != "" {
		cert, e := tls.LoadX509KeyPair(certPath, keyPath)
		if e != nil {
			t.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
		} else {
			pool := x509.NewCertPool()
			t.TLSClientConfig = &tls.Config{InsecureSkipVerify: true, Certificates: []tls.Certificate{cert}, RootCAs: pool}
		}
	}
	client := &http.Client{Transport: t}
	var (
		req *http.Request
	)

	if body != nil {
		req, err = http.NewRequest(method, uri, body)
	} else {
		req, err = http.NewRequest(method, uri, nil)
	}

	if err != nil {
		return
	}

	for k := range header {
		req.Header.Add(k, header[k])
	}

	res, err = client.Do(req)
	return
}

func readBody(res *http.Response) (msg Message, err error) {
	var (
		body   []byte
		reader io.Reader
	)
	encoding := res.Header.Get("Content-Encoding")
	switch encoding {
	case "gzip":
		reader, err = gzip.NewReader(res.Body)
		if err == nil {
			body, err = ioutil.ReadAll(reader)
		}
	default:
		body, err = ioutil.ReadAll(res.Body)
	}
	if err != nil {
		return
	}

	msg.StatusCode = res.StatusCode
	msg.Header = res.Header
	msg.Body = body
	return
}

// Post HTTP request POST
func Post(uri, certPath, keyPath string, header map[string]string, data io.Reader) (msg Message, err error) {
	var res *http.Response
	if res, err = newRequest("POST", uri, certPath, keyPath, header, data); err != nil {
		return
	}
	defer res.Body.Close()
	msg, err = readBody(res)
	msg.Cookies = res.Cookies()
	return
}

// Get HTTP request GET
func Get(uri, certPath, keyPath string, header map[string]string) (msg Message, err error) {
	var res *http.Response
	if res, err = newRequest("GET", uri, certPath, keyPath, header, nil); err != nil {
		return
	}

	defer res.Body.Close()
	msg, err = readBody(res)
	msg.Cookies = res.Cookies()
	return
}

// SetCookie set http cookie
func SetCookie(w http.ResponseWriter, name, value, path string, maxAge int) {
	cookie := &http.Cookie{
		Name:     name,
		Value:    value,
		Path:     path,
		HttpOnly: false,
		MaxAge:   maxAge}

	http.SetCookie(w, cookie)
}